鄂尔多斯长7致密砂岩储层体积压裂可行性评价

Feasibility evaluation of volume fracturing of Chang-7 tight sandstone reservoir in Ordos Basin

从储层岩石矿物组分、岩石脆性指数、天然裂缝发育状况以及体积压裂所需地应力条件4个方面分析了鄂尔多斯盆地长7致密砂岩储层实施体积压裂的可行性。结果表明：鄂尔多斯长7储层岩石石英质量分数为40．3％，脆性指数为35％～50％；储层微裂缝发育概率在60％左右，裂缝密度为3条／10m，天然裂缝及水平层理较发育；水平两向主应力差为4—5MPa，均可满足实现体积压裂复杂形态裂缝扩展的条件。体积压裂井试采效果表明，体积压裂后可形成一定程度复杂缝网。水平井体积压裂技术可成为该储层高效开发的重要措施。

The feasibility of volume fracturing of Chang-7 tight sandstone reservoir in Ordos Basin is theoretically evaluated from four aspects of the rock mineral components,the rock brittleness index,the natural fracture development situation and the crustal stress conditions. The results show that the quartz content of the oil reservoir is 40. 3%,the rock brittleness index is 35% ~ 50%,; the crack development probability is about 60%,the crack density is 3 per 10 meters,natural cracks and horizontal beddings are developed well; the difference between two horizontal principal stresses is 4 ~ 5 MPa. These all meet the conditions for realizing volume fracturing. The test production of the fracturing wells in studied area shows that complex fracture network is formed in the Chang-7 oil reservoir to a certain degree. So the volume fracturing technology of horizontal wells will be important measures for the efficient development of the studied reservoir.